Transformer

ABSTRACT

The present invention relates to a transformer adaptable to electric machines of various types, in which the increase and decrease in the number of sheets of the laminated iron plates is made possible by holding with pressure the corners of the core with suppression plates. Metal plates are applied on the core in such a manner as to enclose it, cover plates are put on the top and bottom of the metal plates, thereby hermetically enclosing the core, the arrangement improves the heat radiation and the dustproof characteristics of the transformer.

United States Patent Konishi June 24, 1975 [54] TRANSFORMER 3,138,774 6/1964 Derbyshire et al. 336/2l0 3,226,664 l2 l965 B tts t. 336 98 X [761 Invent Nllch se'sakusho 3 262 077 71966 W roblewski 3136/2 10 x 4-49-Chome, Osaka, Japan [22] Filed: Jan. 2, 1974 Primary ExaminerThomas .l Kozma Attorney, Agent, or Firm-Armstrong, Nikaido & [2|] Appl. No.. 429,766 wegner [30] Foreign Application Priority Data 5 ABSTRACT 1972 Japan 4748217! The present invention relates to a transformer adaptable to electric machines of various types, in which [52] 336/61; d the increase and decrease in the number of sheets of ,2 the laminated iron plates is made possible by holdin I c1 HOlf 27 26 g [51] 'f 98 55 with pressure the corners of the core with suppression [581 Md 0 each plates. Metal plates are applied on the core in such a manner as to enclose it, cover plates are put on the (56] References cued top and bottom of the metal plates, thereby hermeti- UNITED STATES PATENTS Cally enclosing the core, the arrangement improves 2,l48.449 2/l939 Edwards 336/210 X the heat radiation and the dustproof characteristics of 2,815,49] [2/1957 Antalis et al 336/98 the transformer, 2.845,602 7 1953 Korte 336/2l0 3.011119 11 /l96l Dicrstein 336/210 x 12 Clalms 5 Drawmg Flgurss PATENTEI] JUN 24 I975 SHEET SHEET PATENTEDJUN 24 I975 FIG 4 1 TRANSFORMER BACKGROUND OF THE INVENTION Heretofore, in a transformer of the laminated core type having laminated iron plates in which the number of sheets corresponds to the capacity of the transformer, the laminated iron plates of the core are fitted in a case formed of sheet metal, and clamped, thereby securely holding the iron plates in place. In this arrangement, however, cases of various sizes are required in correspondence to the number of sheets of the laminated iron plates used. Accordingly, the inconvenience of manufacturing a large number of dies to meet the variety of cases is encountered. Moreover. even when the number of steel plates laminated is increased by about 2-3 sheets in order to raise the voltage to a slight degree, the transformer, because of the size of the case used, must be a larger type.

In contrast to such a construction, a conventional transformer is available in which the clamping bolts are pierced through the four corners of the core, and the bolts are detachably clamped, thereby enabling the addition of laminate steel plates. In such a transformer. however, the piercing holes develop a magnetic resistance in the core, and the bolts may sustain a hysteresis loss with the evolution of heat, thereby causing reduction in performance.

In transformers with ferrite cores. fixing with clamps or the piercing of holes, can not be made in the usual manner because of the low strength of the core. This presents a problem in securely holding the core in place.

Furthermore, the matching of the abutting surfaces of the paired core plates, in the transformers with solid cores, can not be made due to the embracing force of the clamping case. For this reason, usually, a setting agent is filled and set all over the outside surfaces of the core, thereby preventing the slip on the abutting surfaces. In this arrangement however the dissipation of heat from the core may be prevented causing a reduction in the performance of the transformer, and many other inconveniences or troubles are involved.

The present invention has, as its objective, the provision of a transformer, in which the corners of the core are held by pressure by means of setting plates. The core is securely held in position without sustaining a hysteresis loss and a decrease and increase in the number of sheets of the laminated iron plates is possible. This construction is applicable also to ferrite cores and solid cores. and has a notable effect in the improvement of performance.

Another objective is to provide a transformer, in which through the improvement in the heat radiation and dust-proofing characteristics, the performance degradation of the core is prevented, thereby greatly enhancing its durability.

SUMMARY OF THE INVENTION According to this invention, end plates are put on the top and bottom surfaces of the core; against the end surfaces and side surfaces of the laminated iron plates along the edges of the four corners of the core. Setting members each provided with two setting plates held at a right angle are pressed, and the coupling bolts are pierced through the end plates and the setting members, thereby securely holding the core.

Another object of this invention is to provide a transformer, in which the core is enclosed by abutting metal plates on the end surfaces of the core. Setting members are put respectively on the outside of each abutted part of the metal plates at each core edge. and the cover plates are placed on the top and bottom. thereby hermetically enclosing the whole. In this manner, the heat radiating surface is enhanced, and the performance of heat radiation and dust-proofing are much improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I shows an oblique view of the transformer of this invention;

FIG. 2 is a sectional view along II--II line of FIG. 1;

FIG. 3 represents an oblique view of a transformer of a second embodiment;

FIG. 4 is a sectional view along lV-IV line of FIG. 3; and

FIG. 5 is a sectional view along V-V line of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the transformer of the first embodiment of this invention as shown in FIGS. I and 2, the transformer body is formed by winding a coil 2 on the core 1 ofthe laminated iron plates. The end plates 3 and 4, formed of an insulating material are put on the top and bottom of this core 1. Holes are made at the four corners of the end plates 3 and 4, through which the coupling bolts 5 are placed. On each side of the surface edge, a setting member 6 is placed, to hold, with pressure. two side surfaces of the core, making a right angle at each core edge.

The aforementioned setting member 6 if formed, for example, by bending a copper plate or by drawing an aluminum plate. A pipe shaped axial hole 7 is formed vertically at the center, and both end edges outside the axial hole project outwardly at a sharp angle approximating a right angle, thereby forming the setting plate 8. Coupling bolts 5 are inserted through the holes 11 at the four corners of the top and bottom end plates 3 and 4, and the axial hole 7 of the setting member 6, so that the core 1 may be held with pressure between the end plates 3 and 4, while the end surface and the side surface making a right angle at each corner of the core 1 are held with pressure by means of respective setting plates 8.

At the rim of the aforementioned bottom end plate 4, fitting screw holes 9 are opened adjacent to the coilwound transformer body and fitting flanges do not project from the transformer body, as in conventional transformers. Because the laminated core I is pressed at its four corners by means of the setting members 6, the laminated iron plates are free of play, and the increase or decrease of the number of sheets of iron plates, if that number of sheets are small, may be accomodated by the elastic deformation of the setting plates 6, or bolts 5 are inserted in the auxiliary holes. through which the bolts pass through. and which are opened in the end plates 3 and 4. In this way. the need of preparing various dies for manufacturing several kinds of cases corresponding to the size of the transformer, which is usually the case, may be obviated, and a small increase in the energizing voltage of the trans former may be very easily made.

FIGS. 3 through 5 show a transformer of a second embodiment. In this transformer, the end surfaces surrounding the core 1 are formed of laminated iron plates. and like the core of the previous embodiment. are enclosed by putting metal plates 10 respectively thereon. At each of the edges of the side surfaces. the aforementioned setting member 6, provided with two setting plates 8 at a right angle. is pressed on the outside surfaces of the metal plates 10. A setting agent such as pitch. etc. is filled in the internal space. as may be required, to stabilize the core in position. The end plates 3 and 4 are put on the top and bottom of the metal plates 10, thereby hermetically enclosing the whole; and then. the coupling bolts are passed through the holes at the four corners of the top and bottom of the end plates and the axial holes 7 of the setting member 6. In this way. the side surface of each metal plate 10 is held by pressure between the setting members. thereby pressing each metal plate 10 against each end surface of the core I. With this construction, the heat evolved at the core may be transferred to the metal plates 10, to be radiated from the whole surface area of the metal plates 10, thus improving the cooling effect. and moreover. preventing dust from entering the coil. Accordingly. there is no requirement for a special dust-proof cover. as in conventional transformers.

As described in the foregoing, in both embodiments mentioned above. the setting plates press the core. and hold it firmly in place by the spring force of the setting surface. For this reason. no bolt inserting holes are necessary in the core. and accordingly. no bolts are inserted through the core. thereby doing away with the undesirable reduction in strength of the core. and the resulting increase in the magnetic resistance and hysteresis loss. When a ferrite core is employed for the core of this invention. the characteristic of this invention may be fully exhibited. and when a solid core is used. a satisfactory magnetic transmission may be expected. because the abutting surfaces are pressure set.

The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive. the scope of the invention being indicated by the appended claims rather than the foregoing description. and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

I claim:

I. A transformer device comprising:

a. a core on which a coil is wound;

b. a plurality of setting plate means each setting plate means approximately equal in length to the height of the core. each said setting plate means including two setting surface means forming a substantially right angle. wherein each said setting plate means engaging only one corner of said core with said set ting surface means pressing against the respective core edges. and thereby firmly holding said core in place; and.

c. two end plate means respectively arranged on the top and bottom of said core. for securely setting the top and bottom ends of said plurality of setting plate means. said end plate means having means for independently adjusting the position of each of said setting plate means for accommodating different size cores.

2. A transformer device comprising:

a. a core on which a coil is wound;

b. setting plate means approximately equal in length to the height of the core. said setting plate means including an axial hole in the lengthwise direction thereof, two setting surface means forming a substantially right angle. wherein said setting surface means presses against the respective core edges. and thereby firmly holds said core in place; and.

c. two end plate means respectively arranged on the top and bottom of said core. for securely setting the top and bottom ends of said setting plate means. each said end plate means including holes corresponding to the respective said axial holes; and wherein said setting plate means are clamped and securely held between the top and bottom end plate means by bolts through the holes in said end plate means and said axial holes of said setting plate means.

3. A transformer defined in claim 2, wherein said setting plate means are integrally formed.

4. A transformer defined in claim 2. wherein said setting plate means are formed by pressing metal plates.

5. A transformer defined in claim 2. wherein said end plate means includes additional holes to accomodate said setting plate means when the thickness of the core is varied.

6. A transformer defined in claim 2, wherein said end plate means includes fitting holes for inserting screws at the rim thereof.

7. A transformer defined in claim 2, wherein one of said end plate means includes terminals for connecting the lead wires of the coil.

8. A transformer defined in claim 2, wherein said core is formed of laminated iron plates.

9. A transformer defined in claim 2. wherein said core is a solid ferrite core.

10. A transformer defined in claim 2, wherein said core is a solid core.

11. A transformer device comprising:

a. a core on which a coil is wound;

b. metal plates. placed on the four sides and end surfaces of said core thereby enclosing said core;

c. setting plate means approximately equal in length to the height of the metal plates; having two setting surface means forming substantially a right angle, said setting surface means pressing against the abutting parts of the metal plate at the core edges thereby holding the core in place; and.

d. two end plate means arranged at the top and bottom of the core and the metal plates. securely setting the top and bottom ends of said setting plate means.

12. A transformer device comprising:

a. a core formed of laminated iron plates. on which a coil is wound;

b. setting plate means nearly equal in length to the height of the core. each setting plate means having an axial hole and two setting surface means forming a substantially right angle along the lengthwise direction thereof. said plate surface means pressing against each core edge. thereby firmly holding said core in place;

c. top and bottom end plate means respectively arranged at the top and bottom of said core. said end plate means including holes corresponding to the axial holes of said setting plate means; and.

d. bolts inserted through the holes of said end plate means and the axial holes of said setting plate means thereby clamping and firmly holding said setting plate means between the top and the bot tom end plate means.

UNETED STATES PA'EENT OFHQ mijmmm Q}? CQRmmm-N Patent No. 3,891,954 Dated June 24, 1975 Inventor(s) ISEO KUNISHI It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover page, Item L597, line 2, change "47 -482171" to --48217l-- Signed and Scaled this fourth Day Of November 1975 [SE AL] Arrest.-

RUTH C. MASON C. MARSHALL DANN Ammng Officer Commissioner ofPalems and Trademarks 

1. A transformer device comprising: a. a core on which a coil is wound; b. a plurality of setting plate means each setting plate means approximately equal in length to the height of the core, each said setting plate means including two setting surface means forming a substantially right angle, wherein each said setting plate means engaging only one corner of said core with said setting surface means pressing against the respective core edges, and thereby firmly holding said core in place; and, c. two end plate means respectively arranged on the top and bottom of said core, for securely setting the top and bottom ends of said plurality of setting plate means, said end plate means having means for independently adjusting the position of each of said setting plate means for accommodating different size cores.
 2. A transformer device comprising: a. a core on which a coil is wound; b. setting plate means approximately equal in length to the height of the core, said setting plate means including an axial hole in the lengthwise direction thereof, two setting surface means forming a substantially right angle, wherein said setting surface means presses against the respective core edges, and thereby firmly holds said core in place; and, c. two end plate means respectively arranged on the top and bottom of said core, for securely setting the top and bottom ends of said setting plate means, each said end plate means including holes corresponding to the respective said axial holes; and wherein said setting plate means are clamped and securely held between the top and bottom end plate means by bolts through the holes in said end plate means and said axial holes of said setting plate means.
 3. A transformer defined in claim 2, wherein said setting plate means are integrally formed.
 4. A transformer defineD in claim 2, wherein said setting plate means are formed by pressing metal plates.
 5. A transformer defined in claim 2, wherein said end plate means includes additional holes to accomodate said setting plate means when the thickness of the core is varied.
 6. A transformer defined in claim 2, wherein said end plate means includes fitting holes for inserting screws at the rim thereof.
 7. A transformer defined in claim 2, wherein one of said end plate means includes terminals for connecting the lead wires of the coil.
 8. A transformer defined in claim 2, wherein said core is formed of laminated iron plates.
 9. A transformer defined in claim 2, wherein said core is a solid ferrite core.
 10. A transformer defined in claim 2, wherein said core is a solid core.
 11. A transformer device comprising: a. a core on which a coil is wound; b. metal plates, placed on the four sides and end surfaces of said core thereby enclosing said core; c. setting plate means approximately equal in length to the height of the metal plates; having two setting surface means forming substantially a right angle, said setting surface means pressing against the abutting parts of the metal plate at the core edges thereby holding the core in place; and, d. two end plate means arranged at the top and bottom of the core and the metal plates, securely setting the top and bottom ends of said setting plate means.
 12. A transformer device comprising: a. a core formed of laminated iron plates, on which a coil is wound; b. setting plate means nearly equal in length to the height of the core, each setting plate means having an axial hole and two setting surface means forming a substantially right angle along the lengthwise direction thereof, said plate surface means pressing against each core edge, thereby firmly holding said core in place; c. top and bottom end plate means respectively arranged at the top and bottom of said core, said end plate means including holes corresponding to the axial holes of said setting plate means; and, d. bolts inserted through the holes of said end plate means and the axial holes of said setting plate means thereby clamping and firmly holding said setting plate means between the top and the bottom end plate means. 